The Marshall JCM900 4100 is a 100-watt, all-tube guitar amplifier head, introduced in 1990 and widely recognized as the definitive Marshall sound of the 1990s rock and metal era.
It is a high-gain, two-channel, dual-reverb amplifier known for its versatility, ranging from bright, clean tones to saturated, biting distortion.

Key Features and Technical Specs:
Power: 100 Watts (switchable to 50W), utilizing four 5881 (or 6L6) power valves and three ECC83 (12AX7) preamp valves.
Channels: Two independent channels (A and B).
Controls: Dedicated Gain, Master Volume, and Reverb controls for each channel, plus shared 4-band EQ (Treble, Middle, Bass, Presence).

In 1992 Marshall released a limited run of 30 year anniversary amplifiers in dark blue tolex with gold piping.
This 900 Series amp is from 1993 and done in that same blue tolex from the factory.
Making it quite rare indeed.
New-reissue 4100's are made in China and sell for $2,500 today.
That's a rip-off imo.
This is the one you want.

Recently serviced with all new JJ Tesla pre-amp and power tubes.
No scratchy pots and sounds fantastic.
Very good condition.
Included is a 2-button footswitch for changing channels and switching reverb on and off.
Also included is a zippered bag with handles for storage and transport.handles for storage and transport.

As for shipping and insurance, I won't know what it will cost to ship from Arizona to where you're located, so once you make the purchase, and before I buy a Reverb shipping label, I may have to ask for more to cover the difference.
I will include screen shots for evidence.
At that point you can agree to spend the little extra or ask me to refund the purchase, no harm, no foul.
Of course I will refund you something back if it ends up being less too.
I'm fair and honest about it.