Eley Tenex Match Pellets.

ELEY Tenex air pellets deliver exceptional accuracy, 30% greater weight control than any competitor, and damage-resistant packaging. The proof of their performance is in their early success: We gave prototype pellets to three elite shooters at the European Championships in Hungary and the ISSF World Cup in Mexico. We came away with four medals and a new World Record.
Stats:
Flat head match pellets
.177 (4.49 / 4.50 / 4.51
Weight: 8.2gr

http://www.eley.co.uk/eley-tenex-air-4-51