Handsets come in various types and models and most of the handsets can house both pre paid and post paid sim cards. Nowadays, there are mobile phones which support both GSM and CDMA technology and both the type of pre paid and post paid sim cards can be inserted into a single phone making it a dual phone with 2 different numbers. Mostly hand sets are readily available in the show room for Pay As You Go handset customers who come to the shop to get both the phone and the number.

The entry of Chinese handsets has been a major threat to the environment and most of these Chinese made hand sets are available at very low prices to the customers. Most people prefer these low priced hand sets from China over the more expensive brand models and use these Chinese mobiles on a use and throw manner and these types of hand sets are highly preferred by Pay As You Go handsets for customers like college students, teenagers and school boys who often change their hand sets from time to time. These hand sets from China are viewed all over the world as a major threat to the environment and are being dumped in the black market as an electronic waste.

The condition becomes worse when the branded hand set owners purchase these low priced hand sets and sell in the market to face the severe competition as the profits and revenue of hand set manufacturing firms are getting flat and most companies are facing losses. To avoid the usage of the hand sets from China, mobile service providers of Pay As You Go handsets and post paid plans announced recently that their Pay As You Go handsets and various other hand sets contain the IMEA number and hand sets having this number only can be used to make and receive calls. However, this move proved ineffective as software's are available online to provide these IMEA numbers to all hand sets in the market.

The market for hand sets have drastically come down as most people in Asia prefer the low price hand sets made from China and recently the pollution control board announced that these hand sets are injurious to the health of the humans and the various body parts get damaged on the usage of these hand sets which are suitable for both Pay As You Go, pre paid and post paid mobile phone customers.