Silver Stripe Transtube, the first official iteration. Good amp!!!
The later Teal Stripe amps were using an early TransTube circuit, Peavey has been at this one for a long time.
I've owned quite a few Peavey amps, LA 400, 3 Backstage Pro with the brushed aluminum side stripes, 1 Backstage Pro Teal stripe, some other Teal Stripe 1-12, a Studio Pro Transtube silver stripe, Envoy, Bandit and Studio Pro Red Stripe, 2 original "fanged" Vypyr 15s, one fanged Vypyr 60 watt tube 1-12, a VIP 3 and a now a VIP 1. Most of them are other people's amps now, probably all of them work too.
If it's the stock speaker, a Scorpion 10 will add a few pounds but it will sound huge. Quick and dirty upgrade.
Seems the word is out on the Scorpions, I used to get 10s and 12s for $40-50, now they are quite a bit higher. Worth it, an overlooked truly great guitar speaker.